Managing Drought-Stressed Cows

If you bought drought-stressed cows or replacement heifers this fall, be ready to apply some extra TLC.

While that holds some long-term positives for those fortunate enough to take advantage, it also offers some short-term management considerations.

“I think the big thing is to realize those animals, from a drought standpoint, can be severely stressed,” says Dan Goehl, a veterinarian at Canton Vet Clinic in Canton, MO. “When an animal is malnourished, the first thing that goes is milk production and the reproductive side of things.”

That means, explains Bob Weaber, Kansas State University Extension cow-calf specialist, that if you bought pairs, you should wean the calves as soon as possible. “Get that nutritional load off the cows.”

Then test your hay and pasture and develop a supplementation program to help those cows regain body condition. “When you think about putting condition back on those cows, energy and protein are the name of the game,” he says.

Particularly protein. If the cows are on lower-quality hay or winter pasture, protein becomes the limiting factor. “So, if you adequately supplement protein, that does two things,” he says. “One, it helps meet the protein requirements of the cow. Then, if you feed the rumen microbes appropriately, you’ll increase the apparent digestibility of the forage.”

The better job the bugs do digesting the hay. the more value the cow gets out of it.

“You can feed that stuff every other day, or every third day, to cut down on labor and fuel costs,” he says. Just double or triple the daily amount and the cows will get along fine.

If the cows are going into winter in their third trimester of pregnancy, energy may be an issue, he warns. Just as with protein, a forage test can help determine how much supplemental energy you’ll need to get your cows into shape to deliver a healthy calf, milk well and breed back in a timely fashion.

Health concerns

Just as with nutritional concerns, there are some health concerns if you’re planning to expand your cowherd with replacement heifers or bred cows, Goehl says. “If you’re bringing them from unknown sources, it’s important to pay attention to disease. And bovine viral diarrhea (BVD) and trichomoniasis would have to be at the top of the list.”

Goehl says those “unknown sources” can be as close as your neighbor down the road. “Even if I’m sitting in northeast Missouri and I’m buying cattle from northwest Missouri, there’s always increased risk when bringing new animals into a herd.”

The trouble is, with both BVD and trich, getting a handle on a possible problem can be complicated. That’s because testing, which Goehl always recommends, sometimes doesn’t tell the whole tale.

“We recommend testing for BVD anytime animals are brought into the cowherd. So, if we’re bringing in replacement heifers, we’re going to test for BVD. If we’re bringing in a bull, we’re going to test for BVD.”
And bred cows? Test them, too. But understand that just because a cow tests negative, it doesn’t mean the calf won’t be persistently infected with BVD when it’s born.

That’s because, if a cow contracts the virus at critical periods in early pregnancy, the fetus can become persistently infected. So the cow may have fought off the infection, but her calf is a disaster in waiting.

Tricky trich

A similar problem exists with trich, which is becoming increasingly more common, Goehl says. Once a bull contracts the disease, he’ll always be a carrier. Testing a bull for trich is relatively easy, but the test isn’t very sensitive, which means multiple tests are sometimes necessary in high-risk situations. But unfortunately, there’s no way to test cows.

What’s more, it’s hard to know you have a trich problem until you preg check or calving season rolls around and you’re left with a bunch of open or late-calving cows.

That’s because trich manifests itself early in the pregnancy, causing the cows to either absorb or slough the fetus in the first 60 days. She’ll then cycle back; if the bulls are still turned out and breed her again, she’ll usually carry the second, late, calf to term, but your nice, tidy three-month calving season gets stretched to five or six months

Usually, by the time a bred cow has a calf, she’s cleared the infection, Goehl says. The danger is in bringing in a first-trimester cow. She has trich and aborts. Your bull breeds her back. She’ll carry the calf but now your bull’s got trich and he starts spreading it in your herd.

And, if you’ve pulled the bulls before she cycles back, she’s open. Either way, you’re on the losing end.

In fact, he says many think that’s how trich made its way into Missouri. “There’s a lot of thought in Missouri that it was an unintended consequence of a drought they suffered out West a few years ago. We brought a lot of those cows into Missouri and a lot of people believe trich came in with those cows.”

Goehl encourages his clients to have a breeding soundness exam (BSE) performed on each bull annually, as well as a trich test, if outside animals have come into the herd. “It’s just too big an expense to have a bull not getting cows bred not to justify having a BSE every year.” And Missouri, like a growing list of states, now requires all non-virgin bulls that change ownership be tested negative for trich.

What’s more, all your other management practices become more critical when expanding your herd from the outside, he says.

“When you’re bringing in these unknown entities, no matter what you’re doing for biosecurity, you’re raising your risk. All those management things you normally do become that much more important. A BSE becomes more important, the vaccination program becomes more important, everything that we normally would do is emphasized that much more.”

In a perfect world, in fact, Goehl recommends that new cattle be managed as a separate herd, at least initially. “If I have a herd of 50 cows and I want to expand to 100 and I bring in 50 from Texas, in a perfect world, I’d manage them as two herds of 50. Then, down the road, commingle them together. But anytime you can go through an isolation period, it’s going to decrease the risk of bringing something into your closed herd.”

Trich is particularly a concern if you’re buying sale barn cows. “If buying cows private treaty, find out if they (the ranch of origin) have been trich-testing bulls, what their bull use is, and get a pregnancy diagnosis on those cows so you know what you’re getting,” Weaber says.

Acclimation issues

“The typical rule of thumb is you can move cattle north and you can move them west a lot easier than you can move them south and east,” Weaber says. That’s principally because of fescue adaptation and weather. If cows are moving north, Weaber says it’s wise to pay attention to breed composition. Short-haired, thin-skinned Brahman crosses from South Texas probably won’t flourish in a North Dakota winter.

While matching genetics and hair coat to weather conditions is important, body condition is the principal winter insulation for cattle, Weaber says. That’s why it’s important to get newly arrived cows up to speed as quickly as possible.

“If they’re a 2, 3 or 4 in body condition, their daily energy requirement goes up pretty dramatically when cold, wet weather sets in,” Weaber says. “One of the best things you can do for those cows is get some condition on them now. Then, as you get into colder weather, feed a high-fiber diet. Make sure they have a full belly. If you can get that rumen microbe population cranking on digesting fiber, that produces a whole lot of byproduct heat to keep those cows warm.”

For cows moving east, Goehl stresses that not all grass is created equal. Cows in Missouri are used to eating fescue and have adapted to the endophyte situation to an extent. Beyond that, however, is the fact that cows from more arid climates and sparser pastures have different grazing patterns.

“The dry-matter content of our Missouri grasses in the spring is very lush and they have to consume large quantities of grass,” he says. “Sometimes it’s hard for those animals to adapt to that new environment.”